The small but stubbornly unyielding possibility of a very large long-term response of global temperature to increases in atmospheric carbon dioxide can be termed the fat tail of high climate sensitivity. Recent economic analyses suggest that the fat tail should dominate a rational policy strategy if the damages associated with such high temperatures are large enough. The conclusions of such analyses, however, depend on how economic growth, temperature changes, and climate damages unfold and interact over time. In this paper we focus on the role of two robust physical properties of the climate system: the enormous thermal inertia of the ocean, and the long timescales associated with high climate sensitivity. Economic models that include a climate component, and particularly those that focus on the tails of the probability distributions, should properly represent the physics of this slow response to high climate sensitivity, including the correlated uncertainty between present forcing and climate sensitivity, and the global energetics of the present climate state. If climate sensitivity in fact proves to be high, these considerations prevent the high temperatures in the fat tail from being reached for many centuries. A failure to include these factors risks distorting the resulting economic analyses. For example, we conclude that fat-tail considerations will not strongly influence economic analyses when these analyses follow the common—albeit controversial—practices of assigning large damages only to outcomes with very high temperature changes and of assuming a significant baseline level of economic growth.

Thursday, September 27, 2012

A new paper published in Geophysical Research Letters "finds that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin." The authors note "The phase of the 60-year oscillation found in the tide gauge records is such that sea level in the North Atlantic, western North Pacific, Indian Ocean, and western South Pacific has been increasing since 1985–1990", meanwhile the figure below shows the eastern North Pacific and SW Pacific phase may have bottomed around the year 2000 and may be on an up phase currently. The authors note that "the possibility [of a 60-year natural cycle] should be considered when attempting to interpret the acceleration in the rate of global and regional mean sea level rise."Climate has also long been known to have a natural ~ 60 year cycle, along with the Pacific Decadal Oscillation [PDO] and Atlantic Multidecadal Oscillation [AMO]. A very simple climate model consisting only of the "sunspot integral" + PDO + AMO predicts 96% of the variation in global temperature [R²= .96], whereas CO2 correlates poorly with global temperature [R² = .44].

We examine long tide gauge records in every ocean basin to examine whether a quasi 60-year oscillation observed in global mean sea level (GMSL) reconstructions reflects a true global oscillation, or an artifact associated with a small number of gauges. We find that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin. Averaging of tide gauges over regions shows that the phase and amplitude of the fluctuations are similar in the North Atlantic, western North Pacific, and Indian Oceans, while the signal is shifted by 10 years in the western South Pacific. The only sampled region with no apparent 60-year fluctuation is the Central/Eastern North Pacific. The phase of the 60-year oscillation found in the tide gauge records is such that sea level in the North Atlantic, western North Pacific, Indian Ocean, and western South Pacific has been increasing since 1985–1990. Although the tide gauge data are still too limited, both in time and space, to determine conclusively that there is a 60-year oscillation in GMSL, the possibility should be considered when attempting to interpret the acceleration in the rate of global and regional mean sea level rise.

A paper published today in Geophysical Research Letters finds there was an "Abrupt change in atmospheric CO2 during the last ice age" which occurred "rapidly, over less than two centuries. This rise in CO2 was synchronous with, or slightly later than, a rapid increase of Antarctic temperature." The authors also report "carbon cycle modeling doesn't capture all of the processes for CO2 variations." Thus, rapid increases in atmospheric CO2 have been shown to occur naturally due to processes not captured by climate models. In addition, temperature rise during the last ice age was found to be synchronous or leading CO2 rise, implying that temperature controls atmospheric CO2, rather than CO2 controlling temperature. Related: Climate scientist Dr. Murry Salby explains why man-made CO2 does not control climate

Carbon-cycle-climate modeling doesn't capture all of the processes for CO2 variations.

Authors:

Jinho Ahn

Edward Brook

Andreas Schmittner

Karl J Kreutz

During the last glacial period atmospheric carbon dioxide and temperature in Antarctica varied in a similar fashion on millennial time scales, but previous work indicates that these changes were gradual. In a detailed analysis of one event we now find that approximately half of the CO2 increase that occurred during the 1500-year cold period between Dansgaard-Oeschger (DO) events 8 and 9 happened rapidly, over less than two centuries. This rise in CO2 was synchronous with, or slightly later than, a rapid increase of Antarctic temperature inferred from stable isotopes.

Wednesday, September 26, 2012

A new paper published in Geophysical Research Letters finds from satellite observations that "Clouds over the Pacific warm pool have a longwave cooling effect for increases in sea surface temperatures." Thus, clouds changes act as a negative feedback to sea surface warming. Climate models, however, erroneously assume clouds and water vapor act as positive feedbacks. The authors find a "strong" increase in outgoing longwave radiation [OLR] to space of 15.72 W/m2 for each 1C change in sea surface temperature. By way of comparison, the IPCC alleges a doubling of CO2 will decrease or "trap" OLR by 3.7 W/m2, a factor of 4 less. According to the authors, "This atmospheric cooling effect is found to be primarily associated with reduced areal coverage of clouds (a 14.4% decrease in cloud cover per 1C change in sea surface temperature).

This study investigated variations in outgoing longwave radiation (OLR) in response to changes in sea surface temperature (SST) over the Pacific warm pool area (20°N–20°S, 130°E–170°W). OLR values were obtained from recent (January 2008–June 2010) geostationary window channel imagery at hourly resolution, which resolves processes associated with tropical convective clouds. We used linear regression analysis with the domain-averaged OLR and SST anomalies (i.e., ΔOLR, ΔSST; deviations from their 90-day moving averages). Results show that the regression slope appears to be significant only with SST least-affected by cloud radiative forcing, for which SST needs to be obtained as daily average over cloud-free regions (ΔSSTclear). The estimated value of ΔOLR/ΔSSTclear is 15.72 W m−2 K−1, indicating the presence of strong outgoing longwave radiation in response to surface warming. This atmospheric cooling effect is found to be primarily associated with reduced areal coverage of clouds (−14.4% K−1).

In a highly recommended lecture, Dr. Murry Salby, professor and Climate Chair at Macquarie University, Australia, debunks the popular myth that man-made CO2 controls global temperature. Dr. Murry proves from observations the opposite is true: natural changes in global temperature instead control CO2 levels and that man-made emissions do not control either atmospheric CO2 or the climate. Dr. Salby also debunks the notion that changes in greenhouse gases control ocean temperatures, showing that the huge heat capacity of the ocean means that a tiny ocean cooling of < 0.0005C could cause all atmospheric warming of < 1C observed since pre-industrial times. Dr. Salby shows why nature, not man, is the cause of the increase in CO2 by demonstrating that only the integral of temperature changes explains the changes in atmospheric CO2, not a slow steady rise in man-made emissions.Significant slides from the presentation are below:

Popular myths

A cooling of the ocean of < 0.0005C could alone account for a 1C rise in atmospheric temperature

A change in radiative forcing due to doubled CO2 is much smaller than the errors in Earth's energy budget assumptions

A new paper published in Quaternary Science Reviews finds that alpine glaciers in Glacier National Park, Montana retreated up to 6 times faster during the 1930's and 1940's than over the past 40 years. The "Multi-proxy study of sediment cores retrieved from lakes below modern glaciers supports the first detailed Neoglacial chronology for Glacier National Park (GNP)" and shows "maximum reconstructed retreat rates [in] 1930" of about 125 meters per year, compared to near zero in ~1975 and about 20 meters/year at the end of the record in ~2005. The authors report, "Results indicate that alpine glaciers in Glacier National Park advanced and retreated numerous times during the Holocene after the onset of Neoglaciation 6,500 years before the present" and "Retreat from the Little Ice Age maximum was the most dramatic episode of ice retreat in at least the last 1000 years."

Fig. 8. Relationship between climate, retreat of the Agassiz Glacier, and flux of carbonate in core UKL-1 from AD 1750 to the present. Dashed line shows CaCO3 flux in mg/cm2/yr. Filled gray line illustrates the reconstructed retreat rate of the Agassiz Glacier from its LIA terminal moraine, calculated from dating of trees in the glacier forefield (Carrara and McGimsey, 1981). Carbonate flux began to rise at the onset of ice retreat, and reached a peak nearly synchronous with the maximum reconstructed retreat rates ca AD 1930. Filled black line presents a tree-ring compilation (BMS Douglas Fir) sensitive to summer drought collected in the vicinity of the Agassiz Glacier (Pederson et al., 2004). Black fill (note reversed scale) denotes wetter, cooler conditions that were responsible for advance of the Agassiz Glacier to its LIA maximum position. Retreat began with the switch to below-normal precipitation.

Abstract

Multi-proxy study of sediment cores retrieved from lakes below modern glaciers supports the first detailed Neoglacial chronology for Glacier National Park (GNP), Montana. Analysis focused on sedimentary properties sensitive to the extent and activity of upstream glacier ice, including: water, organic matter, carbonate, and biogenic silica content; bulk density; mass accumulation rate; phosphorus fractionation; magnetic susceptibility; L*a*b* color values; and grain size distribution. Results indicate that alpine glaciers in GNP advanced and retreated numerous times during the Holocene after the onset of Neoglaciation ca 6500 BP. The two oldest phases of glacier expansion were synchronous with the well-documented Garibaldi (5600–6900 BP) and Tiedemann-Peyto (1900–3700 BP) phases in western Canada. Younger phases correspond with the First Millennium Advance in western Canada, as well as glacier with advances in the Sierra Nevada. The culminating Little Ice Age (LIA) advance was the most recent and extensive of a series of advance/retreat cycles over the past millennium. Retreat from the LIA maximum was the most dramatic episode of ice retreat in at least the last 1000 years.

Highlights

► A high-resolution, lacustrine-based Neoglacial record. ► Neoglaciation began 6500 BP. ► Intervals of expanded glaciers were broadly synchronous within the region. ► Retreat after the Little Ice Age was the most dramatic event of the last millennium.

A paper published today in the Journal of Geophysical Research finds degassing of "relatively large CO2 emissions" from geologic sources occurs through soils, groundwater and local thermal springs in tectonically active regions. The authors measured CO2 emissions up to 6.3 times greater than in "a comparable site that was some distance from fault sites." According to the authors, such "Geologic carbon sources may confound ecosystem carbon balance estimates."

At a semiarid steppe site located in the SE of Spain, relatively large CO2 emissions were measured that could not be attributed to the ecosystem activity alone. Since the study site was located in a tectonically active area, it was hypothesized that a part of the measured CO2 was of geologic origin. This investigation included a survey of soil CO2 efflux, together with carbon isotope analyses of the CO2 in the soil atmosphere, soil CO2 efflux (i.e., Keeling plots), groundwater and local thermal springs. These measurements confirmed the hypothesis of degassing from geologic sources. In areas with local faults and ancient volcanic structures, soil CO2 efflux rates were significantly higher (i.e., up to 6.3 and 1.4 μmol CO2 m−2 s−1) than measurements in a comparable site that was some distance from fault sites (means of 1.0 and 0.43 μmol CO2 m−2 s−1 in March and June, respectively). The CO2 concentration in the soil atmosphere at the eddy covariance site reached 0.14% v/v at 0.70 m soil depth with a 13C-enriched isotopic composition (δ13C from −10.2‰ to −16.6‰), consistent with the isotopic composition of the soil CO2 efflux estimated by Keeling plots (i.e., −16.6‰). 13C-enriched CO2 also occurred in local aquifers, and there was evidence of degassing from deep crust and mantle at regional scale by the helium isotopic ratio in spring waters located about 30 km (R/Ra: 0.12) and 200 km (R/Ra: 0.95) NW of the eddy covariance site. This study highlights the importance of considering CO2 sources of geologic origin when assessing the net ecosystem carbon balance of sites that may possibly be affected by circulation of such CO2-rich fluids.

A paper published today in Atmospheric Chemistry and Physics finds that "a solar proton event, if it took place in the near future with an intensity similar to that ascribed to the Carrington Event of 1859, must be expected to have a major impact on atmospheric composition throughout the middle atmosphere, resulting in significant and persistent decrease in total ozone," resulting in a "significant [global] cooling of more than 3C". The Carrington Event of 1859 lasted only 2 days, but caused persistent changes in ozone lasting up to several months. The authors predict such an event could cause a "cooling of up to 5 K in eastern Europe and Russia to a somewhat smaller decrease of about 3 K for the Southern Hemisphere in Argentina."

Atmos. Chem. Phys., 12, 8679-8686, 2012www.atmos-chem-phys.net/12/8679/2012/doi:10.5194/acp-12-8679-2012Influence of a Carrington-like event on the atmospheric chemistry, temperature and dynamicsM. Calisto1, P. T. Verronen2, E. Rozanov3,4, and T. Peter41International Space Science Institute (ISSI), Bern, Switzerland2Finnish Meteorological Institute, Helsinki, Finland3Physical-Meteorological Observatory/World Radiation Center, Davos, Switzerland4Institute for Atmospheric and Climate Science ETH, Zurich, SwitzerlandAbstract. We have modeled the atmospheric impact of a major solar energetic particle event similar in intensity to what is thought of the Carrington Event of 1–2 September 1859. Ionization rates for the August 1972 solar proton event, which had an energy spectrum comparable to the Carrington Event, were scaled up in proportion to the fluence estimated for both events. We have assumed such an event to take place in the year 2020 in order to investigate the impact on the modern, near future atmosphere. Effects on atmospheric chemistry, temperature and dynamics were investigated using the 3-D Chemistry Climate Model SOCOL v2.0. We find significant responses of NOx, HOx, ozone, temperature and zonal wind. Ozone and NOx have in common an unusually strong and long-lived response to this solar proton event. The model suggests a 3-fold increase of NOx generated in the upper stratosphere lasting until the end of November, and an up to 10-fold increase in upper mesospheric HOx. Due to the NOx and HOx enhancements, ozone reduces by up to 60–80% in the mesosphere during the days after the event, and by up to 20–40% in the middle stratosphere lasting for several months after the event. Total ozone is reduced by up to 20 DU in the Northern Hemisphere and up to 10 DU in the Southern Hemisphere. Free tropospheric and surface air temperatures show a significant cooling of more than 3 K and zonal winds change significantly by 3–5 m s−1 in the UTLS region. In conclusion, a solar proton event, if it took place in the near future with an intensity similar to that ascribed to of the Carrington Event of 1859, must be expected to have a major impact on atmospheric composition throughout the middle atmosphere, resulting in significant and persistent decrease in total ozone.

Abstract: Consumption of all the world’s fossil fuels at any credible rate will not achieve a doubling of the current CO2 level and will increase world temperature by barely one-half degree Celsius. The achievable level of atmospheric CO2 is proportional to its release rate because its dilution by exchange with the land and ocean takes time. An instantaneous release is the worst case and if the entire world’s CO2 from fossil fuels were so released (impossible, of course) it represents an extreme upper bound to the CO2 level. And even that would achieve an increase of less than 3 degrees Celsius. Most significant, however, is the strong evidence that feedback from increased CO2 is negative....

Calculations

The Modtran computer code (4) developed by the Air Force and considered the standard for computing radiation transport in the atmosphere is used to solve the increase in IR energy absorption as a function of increase in CO2 concentration. Modtran is described in Appendix B.

This analysis assumes that Modtran uses sufficiently accurate calculation and atmospheric parameters to produce reliable results. The analysis includes feedback to the extent that results are compared with very different moisture conditions in the atmosphere, and the basis for claimed feedback is the additional atmospheric moisture caused by increased atmospheric CO2.

The elevated temperatures claimed by AGW proponents depend on positive feedback. Water vapor’s greenhouse effect frequently increases more in a day than CO2 can increase in decades.Thus, if positive feedback were possible the world cataclysm that AGW proponents predict would have occurred centuries ago due to water alone.And nature’s feedbacks are predominantly negative.Both history and physics are aligned against the assumption of positive feedback.

Figure 4 shows the Modtran computed IR flux in watts per square meter across the atmosphere in both the upward and downward direction. Upward flow stabilizes and downward flow disappears beyond about 30 km altitude because IR interactions are effectively zero due to the extremely low density of the atmosphere. Where the slope of the deposition is downward in the direction of the radiation, IR is being absorbed faster than it is being generated (by the heated molecules) and the opposite is true for an upward slope.

The “thermals” and “latent heat” shown in Figure 5 entering from the earth’s surface are not IR. That absorbed directly from sun into the atmosphere is radiation, but very little in the IR range. Its frequency degrades in the atmosphere to the IR energy range where it is absorbed as heat. These non-IR components, 17, 80 and 78 watts/m2, respectively sum to 175 and must be added to the IR input value in order to derive a heat balance.

Figure 5. Energy Balance by IPCC (5)

Figure 5 values are similar to other heat balances, such as that by the weather service (6) and NASA (7). But only the IPCC balance of Figure 5 indicates a net heat absorption into the earth, whose existence is highly controversial. The IR exiting the atmosphere to outer space is the only heat loss mechanism of the earth-atmosphere system. Modtran is used to calculate input and output IR energy for all the other levels of CO2 of concern which are indicated in Table 1.

Figure 6 illustrates the baseline case of 400 ppm, the approximate current level of atmospheric CO2.

The heat rate to the atmosphere, H, for each CO2 level is determined with the following calculation:

H = IRin +175 – IRout

Where H is the heat retained in the atmosphere at the particular CO2 level and 175 is the non-IR heat input, This equation forms the basis for calculating temperature rise. To maintain at least a short-term steady state the heat added must be removed and the only mechanism whereby the earth-atmosphere system can remove heat is by radiation to outer space, according to the Maxwell-Boltzmann equation for radiative heat transfer:

H = caTa4 – coTo4

Where subscripts a and o refer to atmosphere and outer space, respectively;

H is heat rate into the atmosphere,

T is temperature in degrees Kelvin.

Ta is the temperature within the atmosphere which would match the aggregate of all radiative transfers to outer space when used in the above equation. In this analysis it is assumed to be the maximum (at the earth’s surface) because that produces the maximum (most conservative) value.

c is a constant (Maxwell-Boltmann constant times emissivity).

Outer space temperature is a factor of 100 lower than the characteristic atmospheric temperature, so that its 4th power is a factor of nearly a billion smaller and the second term on the RHS can be ignored without compromising accuracy. Subscripts b and g refer to conditions before and after the CO2 addition, respectively. Dividing the Hg equation by that for Hb, the constant term cancels out and this simplified equation results:

Tg = Ta*(Hg/Hb)1/4 (1)

Temperature rise due to added CO2 is the difference between Tg and Ta.

Results

Figure 6 is a plot of the temperature rise in the atmosphere as a function of CO2 content and Table 1 summarizes the inputs and results of the computation.

A long period for burning the fossil fuel assures a relatively small maximum CO2 level because of the extra time available for mixing with land and ocean. Under the scenario of maintaining the Figure-1 level of 10 petagrams per year to the atmosphere, the complete depletion of the fossil-fuel carbon occurs at 1000 years.

These scenarios depend on fossil fuels ending abruptly with no diminishing over time. Such scenarios are unrealistic but they ensure that maximum atmospheric CO2 content is not underestimated. The value of 0.5-percent-per-year increase of the fossil input rate to the atmosphere matches the current rate at which CO2 level is increasing in the atmosphere according to Figure 3. A 1.5- percent-per-year value is the maximum increase indicated for carbon insertion of Figure 2.

These small temperature numbers of Table 1 are not likely to be underestimates. It does not appear conceivable that either a half degree C temperature rise or a doubling of current CO2 level could be achieved. Even if all that CO2 could be dumped in instantaneously, less than a 3 oC temperature rise would be seen. The maximum CO2 level and associated temperature rise is proportional to the rate of CO2 input.

In Figure 6, 400 ppm is assumed to be the current CO2 level in the atmosphere and all increases are from the temperature at that level. Figure 6 shows the declining effect of increased CO2, but the most significant result is the dramatic decline in temperature rise caused by increasing atmospheric moisture. The Modtran code description, Appendix B, indicates that the middle curve best represents world average conditions.Top-curve values are those in Table 1 because these are the most conservative.

Figures 7 through 10 show the time-dependent atmospheric CO2 content (as a ratio to the current content) and the resulting temperature rise above the current value as a result of the atmospheric carbon insertion rates indicated in Table 1.

Conclusions

The results show that increased carbon dioxide from the burning of fossil fuels causes an inconsequential impact on world temperature. The most significant conclusion, however, is that increased moisture, the presumed cause of feedback, causes a decrease in the warming effect of CO2 (negative feedback).

Bryce Johnson is a retired professional nuclear engineer in the State of California. His career spanned 45 years work in nuclear power and nuclear weapons research. His education includes: BS(ME), University of Idaho, MS(NE) North Carolina State University and PhD(ME), Stanford University.

According to a new Gallup poll, "Americans' distrust in the media hit a new high this year, with 60% saying they have little or no trust in the mass media to report the news fully, accurately, and fairly. Distrust is up from the past few years, when Americans were already more negative about the media than they had been in years prior to 2004."U.S. Distrust in Media Hits New High Fewer Americans closely following political news now than in previous election years by Lymari Morales Gallup.com 9/21/12 WASHINGTON, D.C. -- Americans' distrust in the media hit a new high this year, with 60% saying they have little or no trust in the mass media to report the news fully, accurately, and fairly. Distrust is up from the past few years, when Americans were already more negative about the media than they had been in years prior to 2004. The record distrust in the media, based on a survey conducted Sept. 6-9, 2012, also means that negativity toward the media is at an all-time high for a presidential election year. This reflects the continuation of a pattern in which negativity increases every election year compared with the year prior. The current gap between negative and positive views -- 20 percentage points -- is by far the highest Gallup has recorded since it began regularly asking the question in the 1990s. Trust in the media was much higher, and more positive than negative, in the years prior to 2004 -- as high as 72% when Gallup asked this question three times in the 1970s.

Tuesday, September 25, 2012

A important paper published today in the Journal of Geophysical Research finds that large quantities of ozone [O3], a "major greenhouse gas," are being produced naturally by an increase in lightning activity "caused by the influx of aerosols from a volcano." According to the authors, "Our findings thus suggest a stronger O3 historical radiative forcing because this link implies lower lightning-generated [nitrous oxide] and lower O3, especially in the upper troposphere, in preindustrial time. Aerosol forcing therefore has a warming component via its effect on O3 production and this component has mostly been ignored in previous studies of climate forcing related to O3 and aerosols."
Prior research has shown that large variations in solar UV activity also control ozone production and that ozone levels could be the main driver of recent climate. Once again, natural variability including changes in ozone, solar and volcanic activity have been shown to be important drivers of climate.

Lightning is extremely sensitive to aerosols when the atmosphere is clean

Aerosol induced lightning increase leads to increase in NOx and ozone

History of ozone forcing and feedbacks need to be better addressed

Authors:

Tianle Yuan

Lorraine A. Remer

Huisheng Bian

Jerald Ziemke

Rachel I. Albrecht

Kenneth Pickering

Lazaros Oreopoulos

Steven Goodman

Hongbin Yu

Dale J. Allen

Tropospheric ozone (O3) is a pollutant and major greenhouse gas and its radiative forcing is still uncertain. Inadequate understanding of processes related to O3 production, in particular those natural ones such as lightning, contributes to this uncertainty. Here we demonstrate a new effect of aerosol particles on O3 production by affecting lightning activity and lightning-generated NOx. We find that lightning flash rate increases at a remarkable rate of 30 times or more per unit of aerosol optical depth. We provide observational evidence that indicates the observed increase in lightning activity is caused by the influx of aerosols from a volcano. Satellite data analyses show O3 is increased as a result of aerosol-induced increase in lightning and lightning produced NOx. Model simulations with prescribed lightning change support the satellite data analysis. O3 production increase from this aerosol-lightning-ozone link is concentrated in the upper troposphere, where O3 is most efficient as a greenhouse gas. Our findings thus suggest a stronger O3 historical radiative forcing because this link implies lower lightning-generated NOx and lower O3, especially in the upper troposphere, in preindustrial time. Aerosol forcing therefore has a warming component via its effect on O3 production and this component has mostly been ignored in previous studies of climate forcing related to O3 and aerosols. Sensitivity simulations suggest that 4-8% increase of column tropospheric ozone, mainly in the tropics, is expected if aerosol-lighting-ozone link is parameterized, depending on the background emission scenario. We note, however, substantial uncertainties remain on the exact magnitude of aerosol effect on tropospheric O3 via lightning. The challenges for obtaining a quantitative global estimate of this effect are also discussed. Our results have significant implications for understanding past and projecting future tropospheric O3 forcing as well as wildfire changes and call for integrated investigations of the coupled aerosol-cloud-chemistry system.